Dating in 1950 compare to 2016
Prior to 2015, the highest monthly anomaly on record for the global oceans was 0.74°C (1.33°F) above the 20 century average, occurring just last year in September 2014.
This all-time monthly record was broken in August 2015 ( 0.78°C / 1.40°F), then broken again in September ( 0.83°C / 1.49°F), and then broken once more in October (0.86°C / 1.55°F)—making three all-time new monthly high global ocean temperature records set in a single calendar year.
The following table lists the global combined land and ocean annually-averaged temperature rank and anomaly for each of the 16 (two tied at #15) warmest years on record.
Much of the record warmth for the globe can be attributed to record warmth in the global oceans.
Record warmth for the year was particularly notable in large parts of the northeastern and equatorial Pacific, a large swath of the western North Atlantic, most of the Indian Ocean where a positive Indian Ocean dipole prevailed, and parts of the Arctic Ocean.
Similar to 2014, some of the Southern Ocean waters off the tip of South America and part of the Atlantic Ocean south of Greenland were much cooler than average, with one localized area in the Atlantic region record cold.
The ocean has a much higher heat capacity than land and thus anomalies tend to vary less over monthly timescales.
Ocean temperatures for the year started with the first three months each third warmest for their respective months, followed by record high monthly temperatures for the remainder of the year as one of the stongest El Niños in the historical record evolved.
This is the largest margin by which an annual global land surface temperature has been broken.
Previously, 1981 had broken the record of 1980 by 0.22°C (0.40°F).
This is the first time in the NOAA record that a monthly temperature departure from average exceeded 1°C or reached 2°F and the second widest margin by which an all-time monthly global temperature record has been broken.
(February 1998 broke the previous record of March 1990 by 0.13°C / 0.23°F.) With the contribution of such record warmth at year's end and with 10 months of the year record warm for their respective months, including the last 8 (January was second warmest for January and April was third warmest), the average global temperature across land and ocean surface areas for 2015 was 0.90°C (1.62°F) above the 20 century average of 13.9°C (57.0°F), beating the previous record warmth of 2014 by 0.16°C (0.29°F).